package day07;

import java.util.Random;

public class Ver {
    public static void main(String[] args) {
        String code=aaa(4);
        System.out.println(code);
    }
    public static String aaa(int len){
        String code="";
        char []chs={'1','2','3','4','5'};
        Random a=new Random();
        for (int i=1;i<=len;i++){
            int index= a.nextInt(chs.length);
            code+=chs[index];
        }
        return code;
    }
}
